title: PKCgamma in Vc and C1/C2 is involved in trigeminal neuropathic pain.
abstract: The aim of the present study was to clarify the involvement of protein kinase Cγ (PKCγ) in the facial neuropathic pain following infraorbital nerve injury. We analyzed the change in PKCγ expression in the trigeminal spinal subnucleus caudalis (Vc) and upper cervical spinal cord (C1/C2) following chronic constriction injury of the infraorbital nerve (ION-CCI). We also studied ION-CCI-mediated mechanical nocifensive behavior in rats. The mechanical head-withdrawal threshold significantly decreased 1 to 14 days after ION-CCI compared with that before ION-CCI and in sham rats. The expression of PKCγ was significantly larger in the ipsilateral Vc compared with the contralateral side in ION-CCI rats 3, 7, and 14 days after ION-CCI. Intrathecal (i.t.) administration of the PKCγ inhibitor chelerythrine prevented an increase in the PKCγ expression in the ipsilateral Vc. Moreover, i.t. administration of chelerythrine annulled ION-CCI-mediated reduction in the head-withdrawal threshold. Taken together, these findings suggest that PKCγ expression in the Vc played an important role in the mechanism of orofacial static mechanical allodynia following trigeminal nerve injury.
authors.affiliation: Department of Orthodontics, Nihon University School of Dentistry, 1-8-13 Kandasurugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Nakajima
authors.forename: Y
authors.initials: Y
authors.lastname: Tsuboi
authors.forename: I
authors.initials: I
authors.lastname: Suzuki
authors.forename: K
authors.initials: K
authors.lastname: Honda
authors.forename: M
authors.initials: M
authors.lastname: Shinoda
authors.forename: M
authors.initials: M
authors.lastname: Kondo
authors.forename: S
authors.initials: S
authors.lastname: Matsuura
authors.forename: K
authors.initials: K
authors.lastname: Shibuta
authors.forename: M
authors.initials: M
authors.lastname: Yasuda
authors.forename: N
authors.initials: N
authors.lastname: Shimizu
authors.forename: K
authors.initials: K
authors.lastname: Iwata
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D053119:Benzophenanthridines / Q000378:metabolism; D002574:Cervical Vertebrae; D003250:Constriction; D005157:Facial Pain / Q000201:enzymology*; D007527:Isoenzymes / Q000096:biosynthesis; D008297:Male; D009915:Orbit / Q000294:innervation; D011480:Protease Inhibitors / Q000378:metabolism; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000201:enzymology; D014275:Trigeminal Caudal Nucleus / Q000201:enzymology*; D061221:Trigeminal Nerve Injuries; D014277:Trigeminal Neuralgia / Q000201:enzymology*
chemical_list: D053119:Benzophenanthridines; D007527:Isoenzymes; D011480:Protease Inhibitors; C016299:chelerythrine; C087857:protein kinase C gamma; D011493:Protein Kinase C